1. Field of the Invention
This invention relates to a process for the production of aqueous dispersion compositions containing
aqueous dispersions of polyurethanes and PA0 optionally poly(meth)acrylates, PA0 carboxyl group-containing, aqueous polymeric thickeners, self-crosslinkable polyorganosiloxanes and crosslinking agents. PA0 (A) aqueous dispersions of polyurethanes (Aa) or mixtures of polyurethanes (Aa) and aqueous dispersions of poly(meth)acrylates (Ab), PA0 (B) carboxyl group-containing, aqueous thickener polymer solutions, PA0 (C) self-crosslinking polyorganosiloxane mixtures and PA0 (D) crosslinking agents for the polyurethanes, for the carboxyl group-containing thickener polymers (B) and, optionally, for the poly(meth)acrylates. PA0 (A) aqueous dispersions of polyurethanes (Aa) or mixtures of (Aa) and aqueous dispersions of poly(meth)acrylates (Ab) with PA0 (B) carboxyl group-containing, aqueous polymeric thickeners and subsequently adding PA0 (C) self-crosslinkable polyorganosiloxanes which have not been previously dispersed in water, and wherein the composition also contains PA0 (D) crosslinking agents for components (A) and (B). PA0 (W) vinyl-group-containing polydimethyl siloxanes having a molecular weight of about 10,000 to 25,000, preferably containing about 0.2 to 10% by weight of vinyl groups which are mostly vinyl-endgroups, PA0 (X) Si-H-group-containing polydimethyl siloxanes having molecular weights of about 1000 to 20,000, preferably having an SiH-content of about 0.1 to 8% by weight, for example, trimethylsiloxy-methylhydrogensiloxy poly-dimethyl siloxanes. PA0 (Y) optionally a low molecular weight, cyclic methyl siloxane compound containing vinyl groups, for example, cyclic methyl vinyl tetrasiloxane and PA0 (Z) a platinum catalyst, particularly platinum-siloxane complexes, of the type obtained by reacting platinum compounds such as platinum halides with vinyl siloxane compounds, preferably of the W type, and used in particular in the form of a solution of the platinum complex in (W) or (X).
The invention also relates to corresponding dispersion compositions and to their use for coating and for printing substrates to form hydrophobic coatings which are crosslinked after drying at elevated temperatures.
2. Description of the Prior Art
A variety of textile substrates are coated by direct coating with polyurethane solutions and dispersions which may be applied in several successive coats. Polyacrylate solutions and dispersions are also used for direct coating.
It is also known that polyacrylate dispersions may be blended with dispersions of silicones and that the resulting mixtures may be applied by direct coating.
According to DE No. 3,105,148 A 1(EP-A 1 58239), dispersions of copolymers of acrylates, ethylene, vinyl acetate and/or other monomers in admixture with silicones of the Si-vinyl/SiH-type may also be applied by direct coating using specified adhesive compounds and PT catalysts for crosslinking.
The use of coating compositions such as these and mixtures thereof involves several disadvantages. On account of their relatively high solubility in organic solvents, polyacrylates and copolymers thereof adversely affect the dry-cleanability of the textile substrates coated therewith. The emulsifiers present in the polyacrylate dispersions or dispersions of the copolymers also have an adverse effect (because of their hydrophilicity) in that they greatly reduce the hydrophobicity and resistance to washing of the coated articles.
Another disadvantage is the use of aqueous silicone dispersions because particularly hydrophilic emulsifiers are thus introduced into the coating mixture.